95 Deville 4.9 electrical problems?

Hello all, i'm new here on the forums. I've got a 95 Deville with a 4.9 with 160,000 on the clock. I'm a professional bull rider and the car is my travelling rig. Over the past few months its developed some sort of electrical issue. It fires up perfectly every time, but when I 1st start it up and start driving, it sputters and bucks and cuts out. It doesnt die completely, but it seems like its only running on a few cylinders. After it warms up for about 10 minutes it is clears up and runs great. What has me thinking its an electrical issue is the same thing happens periodically if I turn on the headlights, or roll down a window while driving. It seems that the extra draw of current from any electronic accessory cuts power from the engine and makes it start cutting out. as soon as that accessory stops drawing current, the car smooths out again. It used to do it occasionally, but lately it has been getting worse. This car goes all over the country, so I want to figure this out before it leaves me stranded. It isnt throwing any codes. Any ideas?